I'm not an expert - my LO is only 15 mnths old. But I am a highschool teacher and have dealt with many Aspergers kids.
From what I understand - Aspergers is on the autism spectrum but doesn't have the severe behaviour and retardation that autism can have.
The students I have known with Aspergers are quite intelligent. They have difficulties with change - for instance, announcing that we are going to leave the classroom to work outside might evoke a panic response. They need to have a stable routine and things like a relief teacher really throw them for a spin. They are capable of writing neatly (even bordering on perfectionism - for instance, if they make a mistake they might need a whole new page to feel "right") and getting good grades, they often have trouble talking in public. In the students I knew it manifested as a form of severe shyness.
I think therapy must help a lot. Some of the children with Aspergers I knew were just lovely, had great senses of humour and you could tell they had made progress. I hope the therapy helps your friends grandkids

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Mel - Loving green mama & wonderful wife to the A team. Living the good life in our surburban, hippy heaven
From little things, big things grow